Isolation, characterization, and genomic analysis of a novel bacteriophage MA9V-1 infecting : a pathogen of root rot.

is one of the primary causative agents of root rot of , which significantly affected plant growth and caused economic losses. With the increasing incidence of antibiotic-resistant bacterial phytopathogens, phage therapy has been garnered renewed attention in treating pathogenic bacteria. However, the therapeutic potential of phage therapy on root rot of has not been evaluated. In this study, we isolated a novel lytic phage MA9V-1 infecting MA9 from sewage and monitored the formation of clear and round plaques with a diameter of approximately 0.5-1.5 mm. Phage MA9V-1 exhibited rapid absorption (>75% in 8 min), a latency period of 20 min, and a burst size of 10 particles per cell. Transmission electron microscopy indicated that the phage MA9V-1 is a new myovirus hosting MA9. Sequencing of phage genomes revealed that phage MA9V-1 contained a linear double-stranded DNA genome of 213,507 bp with 263 predicted open reading frames, including phage structure, host lysing, and DNA polymerase/helicase but no genes of tRNA, virulence, and antibiotic resistance. Our proteomic tree and genomic analysis revealed that phage MA9V-1 shares identity with phage PAU and phage PTm1; however, they also showed apparent differences. Further systemic evaluation using phage therapy experiments on suggested that phage MA9V-1 can be a potential candidate for effectively controlling MA9 infection. Thus, we have presented a novel approach to solving root rot in .